sync: remove use of protobuf extensions in protocol to reduce static init overhead.

chrome/browser/sync/api/sync_data.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/sync/api/sync_data.h"
 
 #include <ostream>
 
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 38 matching lines @@
       id_(id),
       immutable_entity_(entity) {}
 
 SyncData::~SyncData() {}
 
 // Static.
 SyncData SyncData::CreateLocalDelete(
     const std::string& sync_tag,
     syncable::ModelType datatype) {
   sync_pb::EntitySpecifics specifics;
-  syncable::AddDefaultExtensionValue(datatype, &specifics);
+  syncable::AddDefaultFieldValue(datatype, &specifics);
   return CreateLocalData(sync_tag, "", specifics);
 }
 
 // Static.
 SyncData SyncData::CreateLocalData(
     const std::string& sync_tag,
     const std::string& non_unique_title,
     const sync_pb::EntitySpecifics& specifics) {
   sync_pb::SyncEntity entity;
   entity.set_client_defined_unique_tag(sync_tag);
@@ skipping 59 matching lines @@
   }
 
   std::string id = base::Int64ToString(GetRemoteId());
   return "{ isLocal: false, type: " + type + ", specifics: " + specifics +
       ", id: " + id + "}";
 }
 
 void PrintTo(const SyncData& sync_data, std::ostream* os) {
   *os << sync_data.ToString();
 }